<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<!-- <body>
	</body> -->
	<!-- frameset 和body两者只能右一个 -->
	<frameset rows="50%,50%">
		<frameset cols="50%,50%">
			<frame name="top_left" src="top_left.html"></iframe>
			<frame name="top_right" src="top_right.html"></iframe>
		</frameset>
		<frameset cols="50%,50%">
			<frame name="bottom_left" src="bottom_left.html"></iframe>
			<frame name="bottom_right" src="bottom_right.html"></iframe>
		</frameset>
		<noframes>
			浏览器不支持框架集
		</noframes>
	</frameset>
</html>